In the company, seniority-based ranking is emphasized.
The tournament rankings were announced.
There is a strict hierarchy in this company.
It's difficult to rank the employees in order.
He got promoted and moved up in the hierarchy.
In traditional organizations, maintaining the hierarchy is considered important.
New employees act according to the hierarchy.
階級 refers to a social or organizational class or stratum, whereas 序列 focuses on the ordering itself rather than the group divisions.
ランキング is a casual loanword for a ranked list (e.g. a chart), while 序列 suggests a more formal, structural hierarchy within an organization.
序列 is a more abstract, formal term for hierarchical order, whereas 番付 usually names a concrete, published ranking chart like sumo standings.
Compound of 序 (order, preface) and 列 (row, line). The combination conveys the idea of an ordered arrangement or ranking.